Product Overview
Carbon steel round bar is one of the most versatile long products in steel trading: a solid cylindrical section supplied in hot-rolled, cold-drawn, normalized, or quenched-and-tempered conditions. It is the raw material for shafts, pins, bolts, gears, axles, and countless machined parts. Huaxia-Steel supplies carbon steel round bars from 6 mm to 300 mm diameter in AISI 1018, 1020, 1035, 1045, 1050, ASTM A36, S235JR, S355JR, C45, S45C, and equivalent grades — factory-direct from certified Chinese mills.

Specifications
| Parameter | Range | Standard / Tolerance |
|---|---|---|
| Diameter | 6 – 300 mm | GB/T 702, EN 10060, ASTM A29; h9/h10 for cold-drawn |
| Length | 4 – 12 m (random or fixed) | ± 50 mm typical, tighter to order |
| Straightness | ≤ 4 mm/m typical | ≤ 2 mm/m for cold-drawn precision bar |
| Section shape | Round, half-round, peeled | Per drawing |
| Weight per meter | 0.22 – 556 kg/m | Theoretical weight per density 7.85 g/cm³ |
| Cutting | Cold saw / shear cut to length | Burr-free ends, bundle marking |
Available Grades
| Standard | Grades | Typical Use |
|---|---|---|
| ASTM A29 | 1018, 1020, 1035, 1045, 1050 | Machinery, automotive, general engineering |
| DIN EN 10083 / 10025 | C45, S235JR, S355JR | Structural and engineering bar |
| JIS G4051 / G3101 | S45C, S50C, SS400 | Asian machinery and construction |
| GB/T 699 / 700 | 45#, 50#, Q235B, Q345B | Domestic and export general purpose |

Manufacturing Standards
- Hot rolling: continuous cast billet reheated and rolled through roughing and finishing stands; supplied with black or pickled surface.
- Cold drawing: hot-rolled bar is pickled, drawn through a die at room temperature to improve tolerance, surface, and strength.
- Heat treatment: normalized, annealed, quenched-and-tempered, or induction hardened to order.
- Tolerances: commercial tolerance per GB/T 702 or ASTM A29; precision h9/h10 for cold-drawn bar.
Applications
- Machinery shafts, axles, and drive pins
- Bolts, studs, and threaded rods
- Gears, sprockets, and cams
- Pump and valve stems
- Construction reinforcement and anchors
- Automotive and agricultural machinery parts

Quality Assurance
- EN 10204 3.1 mill test certificate with heat number traceability
- Chemical analysis and mechanical testing per heat
- Dimensional inspection: diameter, length, straightness, ovality
- Surface inspection for cracks, seams, and scale
- Optional third-party inspection (SGS, BV, TÜV) before shipment
- Hardness testing for heat-treated bars
Packaging & Shipping
- Bundled with steel strapping; wooden runners for forklift access
- Oiled or VCI-wrapped for sea freight rust protection
- Tagged with grade, heat number, size, and bundle count
- 20ft/40ft container or bulk vessel loading
- Loading photos and weight tally provided before departure
Huaxia-Steel supplies carbon steel round bar from 6 mm to 300 mm in hot-rolled, cold-drawn, normalized, and quenched-and-tempered conditions. Send us your diameter, grade, and quantity for a same-week factory-direct quotation.





